In a component fastening structure described in Japanese Patent Application Laid-Open (JP-A) No. 2012-251583, a circular tube-shaped collar member is attached inside a through-hole of an inner panel. A ring-shaped projection portion projects out at an inner edge portion of the inner panel. A circular-shaped flange portion is coaxially provided to a bolt made of metal, and the flange portion is capable of abutting the ring-shaped projection portion. The ring-shaped projection portion comes into close contact with a lower face of the flange portion when the bolt is fastened. JP-A Nos. 2007-263300 and 2008-304023 also describe technology relating to a fastening structure of a metal member and a resin member.